'Product Blog'

High Strength Metallurgical Graphene (HSMG®) Sheets

Strem Chemicals extends its graphene product line and introduces High Strength Metallurgical Graphene (HSMG®) Sheets. These large-area polycrystalline graphene sheets are manufactured with a metallurgical method based on graphene liquid phase growth.

Monolayer graphene is produced by many methods. The first successful attempt to replace traditional exfoliation technique was demonstrated by Rouff, et al, involving a CVD process on solid copper substrate.[1] Since then, graphene layer grown on different metal substrates has raised graphene research to a new level. Graphene monolayer on copper is also available at Strem Chemicals (06-0274).

For further electronic application or device fabrication, graphene on metal foils must be transferred onto insulating substrates. Using polymethylmethacrylate (PMMA) as a substrate material is regarded as the most popular method. However, transferring graphene onto PMMA is not an easy task. Achieving continuous coverage and preventing surface contamination by polymer residues after the transfer process are some of the challenges of graphene application.

Recently, alternative industrial methods for manufacturing mono- and multilayer graphene sheets have been developed by scientists of Lodz University of Technology in Poland.[3-5] Processing is based on the controlled carbon precipitation from liquid metallic matrices. Prepared graphene sheets have exhibited extremely high mechanical strength and are known as High Strength Metallurgical Graphene (HSMG®).

Adsorption and incorporation of carbon atoms into the crystal structure of copper matrix occurs during the carburization process. Maximum carbon content is significantly lower for liquid copper matrix than for solid state matrix, therefore after heating above the melting point, the metal matrix becomes supersaturated with carbon atoms.

Fig. 1. Hexagonal HSMG® graphene flake

The growth process originates with the nucleation of single hexagonal flakes (Fig. 1) on the metallic substrate. Liquid matrix enables grain rotation and rearrangement during the nucleation process which results in larger grain sizes.

Strem offers HSMG® on PMMA and glass substrates in a variety of sizes:

HSMG® is a semiconducting material, and due to its unique qualities, it is suitable for a variety of applications including energetics, electronics, composites, filtration membranes, car industry, aviation, space industry etc.